Silvopastoral Agroforestry Research Articles

Silvopastoral agroforestry systems for dryland corners in Canterbury farms

Silvopastoral agroforestry systems for dryland corners in Canterbury farms

Influence of two agroforestry systems on the nitrification potential in temperate pastures in Brittany, France

Background and aimsAgroforestry, whereby trees are associated with crops and/or livestock, is expected to mitigate nitrogen (N) losses from agriculture. However, little is known about how nitrification potential, an important process that drives N losses, is affected by agroforestry systems. This study aimed to investigate the effect of different silvopastoral agroforestry systems on soil nitrification potential.MethodsNitrification potential was evaluated in two agroforestry systems (hedgerow and alley cropping) associated with temporary grasslands in Brittany, France. In each system, soil was sampled along a transect spanning from the center of the tree row into the grass alley. Soil nitrification potential was determined ex situ and was explained by univariate and multivariate analysis of variables describing vegetation, physicochemical soil properties, and soil organisms.ResultsNitrification potential differed between the two agroforestry systems and among the positions in relation to the trees. In the alley cropping system, nitrification potential was on average 1.5 times higher in the tree row than at 1.5 and 10 m into the grass alley, while in the hedgerow system, nitrification potential at 1.5 m into the grass alley was on average 40% lower than at 10 m into the grass alley. Nitrification potential was strongly correlated with soil pH, whereas no correlation was observed between nitrification potential and community size of soil nitrifiers.ConclusionOur results point out the diverse effects of agroforestry systems on nitrification, a key soil process that is involved in the regulation of N losses.

Examining factors for the adoption of silvopastoral agroforestry in the Colombian Amazon

Current land use systems in the Amazon largely consist of extensive conventional productivist livestock operations that drive deforestation. Silvopastoral systems (SPS) support a transition to low carbon production if they intensify in sympathy with the needs of biophysical and socio-economic contexts. SPS have been promoted for decades as an alternative livestock production system but widespread uptake has yet to be seen. We provide a schema of associating factors for adoption of SPS based on past literature in tropical agriculture and apply this to a bespoke survey of 172 farms in the Caquetá region of the Colombian Amazon. We find a number of factors which do not apply to this region and argue for a context specific approach. The impact of managing increased market access and opportunities for SPS producers are crucial to avoiding additional deforestation. Further understanding of the underlying antecedents of common factors, such as perceptions of silvopastoral systems, would reduce the risk of perverse policy outcomes.

Multi-species rotational grazing of small ruminants regenerates undergrowth vegetation while controlling weeds in the oil palm silvopastoral system

CONTEXT.Prolonged use of synthetic herbicides to control weeds may cause adverse effects on the environment and human wellbeing. As a mitigation effort, commercial oil palm growers have been encouraged to adopt livestock integration as a holistic approach to manage weeds. Previous studies have suggested utilizing a multi-species livestock grazing may optimize the grazing impacts in silvopastoral agroforestry systems. OBJECTIVEPresent study examined the effects of small ruminant grazing (i.e., goats, sheep and multi-species) on undergrowth vegetation with the following specific objectives: 1) to investigate the effects of small ruminant grazing treatments on undergrowth vegetation composition in oil palm plantations; 2) to examine the variables (canopy cover, grazing treatments, and cycles) that influenced undergrowth vegetation (species richness, coverage, height, and dry weight) in oil palm plantations. METHODSWe established quadrats on experimental plots to detect changes in undergrowth vegetation composition, species diversity, coverage, height, and dry weight resulting from different grazing treatments. RESULTS AND CONCLUSIONSWe found that undergrowth vegetation composition varied between different grazing treatments. The multi-species livestock grazing effectively supress unwanted weeds (i.e., woody broadleaves) compared to single–species livestock grazing (i.e., goats, sheep). The use of single-species livestock grazing is likely to cause oil palm growers to use herbicides to control undesirable weeds. Hence, we concluded managing undergrowth vegetation in oil palm plantations using multi-species livestock grazing is a practical approach, and it should be fine-tuned for example by choosing livestock species based on the targeted objectives and the grazing sequence that will be practiced to regenerate the oil palm silvopastoral system. SIGNIFICANCEMulti-species livestock grazing can reduce oil palm growers' dependence on synthetic herbicides for weed control and optimize land use in oil palm plantation sector. On the other hand, the use of single species, whether goat or sheep-only, has caused unwanted undergrowth to increase after several grazing rotations have been carried out. Therefore, the use of multi-species grazing is a promising biological tool to reduce synthetic herbicide application in environmentally-sustainable oil palm plantations.

Exploring the Potential of White-Rot Fungi Exudates on the Amelioration of Salinized Soils

Soil salinization has a major impact on crop revenue, which may be counteracted by harnessing the microbiota that the soil itself harbors. This study aimed to explore the application of fungi exudates (Trametes versicolor and Pleurotus sajor caju) on the potential relief of salt stress in the performance of Lens culinaris in two different soils (a silvopastoral agroforestry soil and LUFA 2.2). Three salinity levels (8, 16, and 26 mS·cm−1) and three levels of each fungal exudate (1%, 6%, and 12%) were evaluated in a 96-h cross-design experiment. Seed germination was checked daily, and after 96-h, seedling radicle and hypocotyl were measured, along with fresh and dry weights and soil phosphatase activity. The sole application of exudates from neither fungus affected the germination and seedling development of L. culinaris. Salinity alone induced a dose-effect response in all L. culinaris tested endpoints, as expected because conductivities above 8 mS·cm−1 are known to be detrimental for many crop species. Application of exudates to salinized soils improved germination rates at 16 and 26 mS·cm−1 compared to the single respective salinity treatment alone, but mainly in assays carried out in natural soil. In addition, under the same conditions (26 mS·cm−1 and all fungi %), there was an improvement in natural soil acid phosphatase activity. The application of rot fungi exudates demonstrates potential in what might prove to be a sustainable measure to reclaim salinized soils and improve crop productivity, which is consistent with current soil protection policies.

Microclimate Drives Shelter-Seeking Behaviour in Lambing Ewes

Silvopastoral agroforestry and the strategic placement of trees and hedgerows offers potential to improve livestock welfare and production efficiency through the provision of shelter in livestock farming systems. The aim of this study was to investigate the relationship between shelter-seeking behaviour of ewes during the lambing period and the microclimate influenced by landscape shelter features. Artificial and natural shelter was provided to Aberfield ewes (n = 15) on an upland sheep farm in Wales, UK, which were then continuously monitored for 14 days using global positioning system tracking devices. Modelling of microclimate influenced by topographical shelter features at the test site was used to generate a 1 m resolution wind field for geospatial statistical analysis of localised wind speed. Ewes demonstrated an increased preference for natural (3.4-fold; p < 0.01) and artificial (3.0-fold; p < 0.05) shelter zones five times the height of the shelter, compared to the exposed area of the trial site. Wind-chill and modelled local-scale wind speeds were found to have the greatest influence on shelter-seeking behaviour, with temperature and field-scale wind speed significantly influencing livestock behaviour. Mean wind-chill temperature during the trial was 3.7 °C (min −5.3 °C; max 13.1 °C), which is within the cold stress temperature threshold (−3 and 8 °C) that requires thermoregulatory strategies such as shelter-seeking behaviour. An improved understanding of the relationship between microclimate and shelter-seeking behaviour in sheep, demonstrated through the agent-based model developed in this project, shall better inform the economic incentives (e.g., reduction in lamb mortality and forage requirements) behind silvopastoral practices that benefit farm productivity, livestock welfare and the environment.

Collaborative agroforestry to mitigate wildfires in Extremadura, Spain: land manager motivations and perceptions of outcomes, benefits, and policy needs

Wildfires are increasing in severity, and magnitude in the Mediterranean Basin in recent years, reaching a yearly average of 450 000 ha over the last decade. Drivers include climate change, land-use change, and land abandonment. Wildfire mitigation requires landscape-level action as impact to each parcel is affected by the conditions of the others. We conducted a case study of a regional-level initiative that develops community efforts to mitigate wildfires through silvo-pastoral agroforestry systems, using an integrated landscape management approach. This approach involves collaboration among stakeholders to achieve multiple objectives. In order to derive insights into its potential, we asked participating land managers: (1) What motivates their participation?, (2) How do they perceive initiative outcomes?, and as urban outmigrants with non-traditional goals are increasing in rural areas, (3) Do responses differ between rural and neo-rural participants? Our results show that managers feel highly affected by wildfires and are strongly motivated to reduce wildfire risk. Land abandonment and inappropriate policy were major concerns. The initiative was seen to have positive outcomes for individual participants as well as the region, and to stimulate community connectedness. We conclude that fit to local contexts, integrated landscape management can be a well-received approach to reducing wildfire risk. Agroforestry systems in Extremadura can act as “productive fuelbreaks” that reduce fire risk over extensive areas, while restoring traditional landscapes. We suggest that programs to reduce wildfire risk can also be used as a leverage point for financing rural revival and provision of multiple ecosystem services.

Adoption of Silvopastoral Agroforestry System for a Sustainable Cattle Production in Nigeria

Silvopastoral systems are agroforestry systems that involves a combination of tree growing with the production of livestock. This type of agroforestry system has the potential to improve hydric balance, enhances biodiversity conservation, increases organic livestock proximity index, allows cleaner cattle production, improves cattle production per hectare, improves carbon sequestration, reduce greenhouse gases and significantly reduce /eliminate herder -farmer conflicts in Nigeria . Hence, this paper reviews and introduces the adoption of silvopastoral agroforestry system for a sustainable cattle production in Nigeria using literatures. Types of silvopastoral systems includes Fodder bank systems, live fence or boundary systems, hedgerow intercropping systems and tree plantation with animal grazing systems. There is limited information on silvopastoral system in Nigeria, hence the need to carry out more research and studies on its acceptability and sustainability in the future.

Agroforestry in the Czech Republic: What Hampers the Comeback of a Once Traditional Land Use System?

The interest in re-implementing agroforestry (AF) in European agriculture due to its environmental benefits has been growing exponentially. We reviewed the historical background and the current state (extent, farmers’ perception, legislative support, and barriers) to evaluate the future perspectives of AF in Czechia by identifying the key factors hampering further extension. Our results confirmed that AF almost disappeared after the middle of the 19th century due to agricultural intensification and collectivization. Currently, AF is not defined in the Czech legislation and no modern AF has been encountered by this study. Areas falling into AF definition recently comprise only traditional AF (less than 1% of agricultural area remaining) represented only by silvopastoral AF. The results of a farmers’ survey indicated that despite relatively high interest in AF, excessive bureaucratization, high costs of establishment and uncertain profitability are severe concerns among farmers. We therefore conclude that there is a lack of legal recognition and marginalization of AF as the key obstacles of low adoption rates. We suggest that systematic support beyond subsidies should include raising awareness, research, policy, legislation changes, training, and advisory service, as a cornerstone for progressive development of AF and thus conservation and creation of economically and environmentally sound landscapes throughout Czechia.

Time to Revisit Oil Palm-Livestock Integration in the Wake of United Nations Sustainable Development Goals (SDGs)

To date, the idea of using livestock animals as biological tools to manage weeds, sequester carbon, and boost food security in oil palm plantations has not been seriously considered by industry stakeholders of major producing countries (e.g., Indonesia, Malaysia, Thailand, Colombia, and Nigeria). We revisit the integration of oil palm cultivation with livestock farming as a silvopastoral agroforestry practice in the wake of Sustainable Development Goals (SDGs). Oil palm-livestock integration has the potential to promote sustainable palm oil production because it can provide multiple environmental and socio-economic benefits, including carbon sequestration, restoring top soil, improving ecosystem biodiversity, reducing pesticide and fertilizer inputs, and boosting national food security. In contrast to monocultural outputs of most conventional plantations, an oil palm silvopastoral system is an ideal way to address the global food insecurity challenge as it produces bioenergy, vegetable oil/fat and animal-based protein sources (e.g., red meat). In addition, the potential of contract targeted grazing could be considered as a new type of business and income diversification for rural people. Oil palm-livestock integration is a strategy by the palm oil industry to achieve multiple SDGs. Out of the 17 SDGs, oil palm-livestock integration is likely to deliver nine SDGs. Palm oil certification bodies should recognize oil palm-livestock integration as a biological control method in weed management practices. We recommend that oil palm-livestock integration should be promoted to revitalize sustainable palm oil production and strategic biodiversity conservation policy. Policy makers should encourage major players in the palm oil industry to practice oil palm-livestock integration.

Trace element composition of tree fodder and potential nutritional use for livestock

Silvopastoral agroforestry, the integration of trees into livestock production systems, is an ancient practice with benefits to animal welfare and nutrition. Intensification of farming practices have reduced the presence of trees and hedgerows in the agricultural landscape. Environmental benefits coupled with improvements to ecological resilience and the long-term sustainability of farm productivity have led to a resurgence in interest in silvopastoral farming systems. The objective of this study was to investigate the nutritional composition and potential use of tree leaves as a supplementary fodder for ruminant livestock, with particular reference to sheep.Leaves (including petioles) were collected during spring (June) and autumn (September) from goat willow (Salix caprea), oak (Quercus spp) and alder (Alnus spp) from three sites in the UK. On the third site samples of ash (Fraxinus excelsior), beech (Fagus sylvatica), sweet chestnut (Castenea sativa) and sycamore (Acer pseudoplatanus) were also collected. Tree leaves were analysed to determine mineral content, dry matter (DM), crude protein (CP), modified acid detergent fibre (MADF) and metabolisable energy (ME) which were then compared to the nutritional requirements of grazing sheep (Ovis aries).Leaves from all tree species used in this study were able to exceed the dietary ME and CP concentration requirements (NRC) for growing lambs (40 kg lamb @ 150 g/d). Alder contained the most ME and CP of the studied species. There was no significant effect of season although CP was higher in spring than autumn for all tree species.Zinc and cobalt concentrations were found to be dependent on tree species with negligible site and season effects. All (NRC) sheep requirements of both elements were exceeded by willow, met by alder and not met by oak, willow exceeded these requirements for zinc and cobalt by approximately 3-6 and 10-15 fold respectively. Leaf selenium concentrations were site specific with site 1 almost able to meet maximal requirement, whilst all other sites (all tree species) were around the minimal requirement.To conclude, ME and CP concentrations of the tree leaves were generally within a requirement range to support adequate growth of lambs if leaves fed alone (not likely in practice). Selenium concentrations were site dependant, iodine was mainly season dependent with tree species effects for zinc and cobalt. The zinc and especially cobalt concentrations of willow leaves were sufficient to suggest that willow could be used as a bio-supplement when fed within a conventional grazing system, especially useful for growing lambs.

Hydraulic redistribution by hybrid poplars (Populus nigra x Populus maximowiczii) in a greenhouse soil column experiment

AimsHydraulic redistribution (HR) enhances water resources for neighboring crops in silvopastoral agroforestry (AF). Here, we tested whether and to what extent water stressed shallow-rooted neighboring plants benefit from water redistributed by deep-rooted poplar plants.MethodsWe conducted trace experiments with deuterated water (2H2O) in greenhouse soil column experiments. We measured hydraulic lift (HL) by poplars grown at two levels of soil drying and estimated the amount of hydraulically lifted water. In a parallel experiment we grew poplars and barley (Hordeum vulgare) in two columns connected via a small cross-rooting segment.ResultsSoil moisture measurements and stable isotope signatures of soil and xylem water proved the occurrence of HL in poplar. Additionally, stable isotopes proved the transport of water from deep roots of poplars to shallow roots of barley.ConclusionsIn conclusion, the experiments showed that poplars are capable to redistribute water during drought spells and that this water can facilitate plant growth of shallow-rooted crops. This result implies evidence for an enhanced soil water supply of plants in agroforest systems under drought conditions.

Silvopastoral production as part of alternative food networks: Agroforestry systems in Umbria and Lazio, Italy

ABSTRACT Silvopastoral agroforestry systems combine the management of livestock and trees or other woody perennials on the same land. Aside from giving farmers an opportunity to diversify their income and reduce inputs, these systems have been shown to provide a number of ecological benefits. Given the growing demand for environmentally produced food, this paper assessed how farmers of silvopastoral agroforestry systems distribute their products in the context of alternative food networks (AFN). Applying Global Production Network (GPN) analysis, the distribution of output was assessed for eight farms in two Italian regions (Umbria, Lazio) following qualitative interviews. While farmers of the case studies partly rely on conventional supply channels and markets, all of them engage in alternative forms of food distribution, such as off-farm sales, home deliveries, and farmer-owned shops enabling direct exchange with customers. Paired with a focus on high product quality, it can be argued that these farmers also form part of alternative food networks. This practice does result in higher prices for directly marketed products, an easier management of product information at the point of sale, as well as high levels of traceability. Yet, the fact that only a few farmers advertise the environmental benefits of their production systems indicates some potential for further value enhancement, which could allow farmers to capitalize on the synergy of alternative production and distribution.

Patchy landscapes support more plant diversity and ecosystem services than wood grasslands in Mediterranean silvopastoral agroforestry systems

Plant diversity and proxy indicators of ecosystem services were assessed for three structural components of Mediterranean silvopastoral agroforestry systems: WL = cork oak woodlands, WG = cork oak wood grasslands, and OG = open grasslands. Our study was conducted in a long-term observatory located in NE Sardinia, characterized by fragmented land ownership and land use, which generates a patchy landscape that is different from the extensively studied large scale Iberian dehesas and montados. Our research question was focused on assessing whether, a “patchy” land use scenario made of the combination of WL, WG and OG or a “specialized” scenario could provide more plant diversity and ecosystem services than a “dehesa type” scenario including only WG under the same overall tree cover. The results showed that γ and β diversity, species unique to a position, C stock, cork and acorn production, Hemicryptophytes cover, nectariferous species cover, decreased and pastoral value, excellent and good forage species and legume cover, increased along the WL➔WG➔OG land use gradient. Isolated trees in WG and clearings in WL highly contributed to achieving mainly high C stock and plant diversity respectively. The results also showed that the “specialized” scenario can support higher biodiversity and better ecosystem services than the “dehesa type” scenario, but the “patchy” scenario made of all three components proved to support the highest level of both biodiversity and ecosystem services in Mediterranean silvopastoral agroforestry systems.

Capturing the value of ecosystem services from silvopastoral systems: Perceptions from selected Italian farms

Combining livestock and trees in silvopastoral agroforestry systems has shown to be valuable in fostering the provision of ecosystem services. For farmers, these systems provide an opportunity for diversifying their product range. This study assessed if farmers can additionally translate the ecological value into economic benefits. Applying the concepts of global value chain (GVC) and global production network (GPN) analysis, the evolution of value was analysed for eight farms in the Italian regions of Umbria and Lazio following qualitative interviews. Production benefits and ecosystem services resulting from the silvopastoral systems were perceived to contribute to product value either by (i) minimising inputs or (ii) adding value through the marketing of quality attributes such as environmentally friendly production or nutritional value. Although ecological benefits of the systems are recognised by most farmers of this study, few advertise it. Due to a lack of possibilities to label products from silvopastoral systems as such, farmers must rely on close connections to consumers for marketing or use organic certification if selling over greater distances. Designing public payments to reward the provision of ecosystem services directly could make silvopastoral farming more attractive and encourage wider application.

BIOECONOMIC POTENTIAL FOR SILVOPASTORAL AGROFORESTRY SYSTEM IN NORTH WALES

Purpose: This study evaluated the bio-economic potentials of temperate lowland silvopastoral agroforestry systems in North Wales, United Kingdom.Methodology: The bioeconomic analysis compared three land-use plausible scenarios (‘forestry’, ‘pasture / livestock’ and ‘agroforestry’) at 3.5% discount rate on a 10-hectare farm over a 30-year rotation using discounted cash flow analysis and national costs and prices for both livestock and tree products based on 2016 baseline data. Base case net present value (NPV) and annual equivalent value (AEV) were calculated for each production livestock grazing, farm forestry, and silvopastoral agroforestry scenario, assuming no policy interventions.Findings: Generally, results of the economic analyses indicated that under the baseline case, assuming no policy interventions, none of the options was viable. This study also showed that increase in lamb sale price, wood price, and wood yield improved the economic viability of the three investment options significantly. Again, the viability of the three investment options in this study is shown to decrease with increase in discount rates. Furthermore, this study disclosed that the application of prevailing government grant/subsidy schemes significantly improved the economic viability of the three investment options as livestock, forestry and agroforestry options showed positive NPV and AEV values at the baseline assumptions and are therefore adjudged economically viable as they all met the decision rule criteria for investment acceptance. Forestry was the most viable option with the highest NPV and AEV, followed by pasture/livestock and agroforestry options.Unique contribution to theory, practice and policy: This study underscored the imperative need for policy makers to improve awareness of the benefits of grant incomes and address farmers’ concerns about the economic viability of livestock, forestry and agroforestry investments. The results of this research will help promote greater awareness of the economic value of trees in extensively grazed landscapes in the United Kingdom as well as provide a basis for future comparisons and analysis of farm programs and ecosystem service markets.

Caracterización estructural de una comunidad arbórea de un sistema silvopastoril en una zona de transición florística de Nuevo León

Las comunidades arbóreas con sistemas silvopastoriles desempeñan un papel importante en los ecosistemas áridos y semiáridos del país, al conservar la biodiversidad y el desarrollo de las actividades ganaderas, que son de vital importancia en el norte de México. Con el objetivo de caracterizar una comunidad arbórea de un sistema silvopastoril en una zona de transición de matorral espinoso tamaulipeco y mezquital en Nuevo León, se establecieron cinco sitios de muestreo de 2500 m2, en los cuales se realizó un inventario de todas las especies arbóreas con diámetro a la altura de 1.30 m (DAP) igual o mayor que 7.5 cm. Se evaluaron composición y estructuras vertical y horizontal a través de parámetros estructurales de la vegetación (abundancia relativa, frecuencia relativa, dominancia relativa), índice de valor de importancia, índice de valor forestal y modelos para las variables diámetro normal - área de copa. Las especies principales desde el punto de vista ecológico fueron Prosopis laevigata (Hump. & Bonlp. ex. Willd.) M. C. Johnst. y Ebenopsis ebano (Berland.) Barneby & J. W. Grimes, la comunidad presentó alta densidad de individuos, alta cobertura de copa y una estructura vertical con alta proporción de individuos con altura mayor o igual a 6 m. El modelo lineal mostró los mejores ajustes al presentar un R2 = 0.621. El manejo silvo-pastoril ha conservado y promovido los atributos estructurales de la comunidad vegetal nativa.

Productivity and economic evaluation of Willow (Salix alba L.) based silvopastoral agroforestry system in Kashmir valley

Performance of two fodder crops namely, sorghum (Sorghum vulgare L.) and maize (Zea mays L.) was investigated with Willow (Salix alba L.) to evaluate productivity and economics of the silvopastoral agroforestry system in Kashmir valley. The experiment was laid out by planting two year old willows at 2.0m × 2.0m spacing and dividing the main plot into sub-plots of size 8m × 2m each with 5 replications in randomized block design (RDB). The intercrops of sorghum and maize were maintained at 20cm × 10 cm spacing and supplied with recommended doses of fertilizers. The economics of the willow plantation intercropped with fodder crops was compared with sole willow farming by the benefit-cost ratio and net present worth. The study revealed the differential behaviour of Salix alba regarding growth parameters (height, diameter and girth) by different intercrops and various fodder intercrops with respect to yield, above ground biomass, dry matter production and soil nutrient status (pH, organic carbon, available nitrogen, phosphorus and potassium). The willow based silvopastoral system was estimated to have benefit-cost ratio of 2.71 with maize and 2.68 with sorghum, while as sole crop the willows accrued a benefit-cost ratio of 2.66. The study is useful in discovering growth of willows, productivity of fodder crops and soil nutrient status under various silvopastoral agroforestry systems for maximizing economic gains. The findings envisaged evidences in favour of adopting willow based silvopastoral agroforestry instead of sole tree farming and the knowledge of interactions will be helpful in proper management of the system for sustained multiple productions.

Understanding agroforestry practices in Europe through landscape features policy promotion

Agroforestry understood as the combination of a woody component (forest tree, shrub, fruit tree) with an agricultural use of the understory is not clearly identified as such by the European Common Agricultural Policy (CAP). Despite the protection and promotion of the woody component in different parts of the CAP political text, the identification of agroforestry is not clear, although it can be recognised in the description of some landscape features, such as isolated trees and different types of hedgerows. Moreover, it is important to identify the extent of such woody components promoted by the CAP in agricultural lands to validate the impact of current and future measures. This paper aims at the characterisation of the current extent of landscape features all over Europe by analysing the Rural Development Program (RDP) measures within the CAP 2007–2013 and 2014–2020 that promote said features in Europe to increase the ecosystem service delivery. Isolated trees and hedgerows are protected unsatisfactorily through the Cross-compliance and Greening of CAP Pillar I. In contrast, Agri-environment measures associated to Pillar II are used in most European countries to protect both isolated trees and hedgerows and to promote them as boundary elements. The promotion of hedgerows and isolated trees mainly related to silvoarable and silvopastoral agroforestry practices is aimed at the promotion of the ecosystem services (such as water protection and biodiversity) and improvement in resilience (such as adaptation to climate change) they provide; therefore, the agroforestry environment benefits are indeed recognised. Landscape features comprising woody perennials should be associated with agroforestry when present in arable and permanent grasslands.

Soil carbon changes after establishing woodland and agroforestry trees in a grazed pasture

This study determined the effect of two tree planting methods (woodland and a silvopastoral agroforestry system) on the soil bulk density and organic carbon content of a grassland site in lowland England. Soil organic carbon was measured in pasture, silvopastoral tree, and woodland treatments at six depths representative of 0–150cm. Fourteen years after tree planting, the organic carbon content in the surface soil layer (0–10cm) was greatest in the pasture (6.0g 100g−1) and least in the woodland (4.6g 100g−1); the value (5.3g 100g−1) below the silvopastoral trees was intermediate. In the 10–20cm layer, the organic carbon content in the woodland was 13% lower than the pasture. No treatment effects on soil carbon were detected below 20cm. Possible reasons for the decline in surface soil carbon include a decline in grass cover and reduced soil water content. Measurements of above ground carbon storage by the trees indicated that tree planting increased overall carbon storage, with the silvopastoral system predicted to achieve a higher level of carbon storage than equivalent areas of separate woodland and pasture. A power analysis indicates that a prohibitively large number of replicates is needed to ensure a lower than 20% risk of falsely concluding no treatment differences at individual depth increments below 10cm and cumulative depths extending below 40cm.